The Ashgate Research Companion to Planning Theory. Conceptual Challenges for Spatial Planning, Hillier J., Healey P. (eds.) (2010), Farnham: Ashgate, 520 pages. ISBN 978-0-7546-7254-8

As it is put in evidence on p. ii, “The companions’ editors bring together a team of respected and experienced experts to write chapters on the key issues in their speciality, providing a comprehensive reference to the filed.” This is what Hillier and Healey try to do in this Companion, which “is Companion to the three volumes, Critical Essays in Planning Theory.” (p. 2) As Hillier puts it in the Introduction, the Companion “is concerned with conceptual challenges for planning theory – including concepts such as contingency, complexity, subjectivity, schemes of signification, creativity, etc. and the challenge of reconceptualizing or retheorizing planning practice – and for planning practice and its key concepts such as sustainability, multiculturalism and so on.” (p. 13) This general purpose informs the three parts of the Companion, that is: “i. Part One, issues from practice to which planning theorists should give attention; ii. Part Two, key concepts in current theorizing from mainly poststructuralist perspective; iii. Part Three, what discussion on complexity may offer planning theory and practice.” (p. 22)